Nonmagnetic impurity substitutions impact on superconducting properties in various ways depending on the pair-breaking mechanism. The aim of the proposed experiment is to understand the effect of such substitutions in ZrB12, a dodecaboride superconductor, and to test a recent suggestion [N. E. Sluchanko et al. Phys. Rev. B 93, 085130 (2016)] that static magnetic moments can be induced by non-magnetic impurities. We have carried out some preliminary measurements at PSI which confirm that Lu-substituted ZrB12 is an ideal system to study using muons. Our results show that there is a large change in relaxation rate on entering the superconducting state, pointing to a relatively low penetration depth, making these measurements ideally suited to ISIS where we can, in addition, take advantage of the high data rate.